You have an algae problem brought on by a temporary excess of nutrients. This sometimes happens in new NPTs. If it is severe, then we'll need more tank details. If it isn't severe, then a little tinkering may solve the problem. A few suggestions to try....remove algae-infested leaves, change water, add charcoal to the filter, add snails and/or algae eating fish, or buy floating plants.
Sometimes NPTs need a little help the first few months. If some of your plants are doing well, then there's hope.